PM / Domains: Fix pm_genpd_poweron()

The local variable ret is defined twice in pm_genpd_poweron(), which
causes this function to always return 0, even if the PM domain's
.power_on() callback fails, in which case an error code should be
returned.

Remove the wrong second definition of ret and additionally remove an
unnecessary definition of wait from pm_genpd_poweron().

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index be8714a..e18566a 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -80,7 +80,6 @@
 int pm_genpd_poweron(struct generic_pm_domain *genpd)
 {
 	struct generic_pm_domain *parent = genpd->parent;
-	DEFINE_WAIT(wait);
 	int ret = 0;
 
  start:
@@ -112,7 +111,7 @@
 	}
 
 	if (genpd->power_on) {
-		int ret = genpd->power_on(genpd);
+		ret = genpd->power_on(genpd);
 		if (ret)
 			goto out;
 	}